Substrate processing devices that perform various types of processes on thin resin substrates are known in the art. A substrate processing device includes, for example, a cleaning unit that cleans the surface of a substrate and a film formation unit that forms a metal film on the surface of the cleaned substrate. For example, the cleaning unit sputters the surface of the substrate to remove foreign matter from the surface of the substrate. Further, the substrate processing device includes a transportation unit that transports the substrate between the cleaning unit and the film formation unit. The transportation unit holds the substrate upright and substantially extending in the vertical direction when transporting the substrate.
The cleaning unit includes a vacuum tank that is connected to ground. The substrate is supported by the transportation unit in contact with a stage inside the vacuum tank. In this state, high-frequency voltage is applied to the stage. As a result, the stage that includes the substrate functions as a cathode and the portion of the vacuum tank that opposes the cathode functions as an anode. Plasma is generated around the substrate from the gas supplied to the chamber. The positive ions in the plasma are sputtered against the surface of the substrate. This cleans the surface of the substrate (refer to, for example, patent document 1).